pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / queries / src / java / org / apache / lucene / search / similar / MoreLikeThisQuery.java

diff --git a/lucene-java-3.5.0/lucene/contrib/queries/src/java/org/apache/lucene/search/similar/MoreLikeThisQuery.java b/lucene-java-3.5.0/lucene/contrib/queries/src/java/org/apache/lucene/search/similar/MoreLikeThisQuery.java
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+/*
+ * Created on 25-Jan-2006
+ */
+package org.apache.lucene.search.similar;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.io.IOException;
+import java.util.Set;
+
+import org.apache.lucene.analysis.Analyzer;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.BooleanClause;
+import org.apache.lucene.search.BooleanQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.similar.MoreLikeThis;
+
+import java.io.StringReader;
+
+/**
+ * A simple wrapper for MoreLikeThis for use in scenarios where a Query object
+ * is required eg in custom QueryParser extensions. At query.rewrite() time the
+ * reader is used to construct the actual MoreLikeThis object and obtain the
+ * real Query object.
+ */
+public class MoreLikeThisQuery extends Query {
+  
+  private String likeText;
+  private String[] moreLikeFields;
+  private Analyzer analyzer;
+  private String fieldName;
+  private float percentTermsToMatch = 0.3f;
+  private int minTermFrequency = 1;
+  private int maxQueryTerms = 5;
+  private Set<?> stopWords = null;
+  private int minDocFreq = -1;
+
+  /** @deprecated use {@link #MoreLikeThisQuery(String, String[], Analyzer, String)} instead. */
+  @Deprecated
+  public MoreLikeThisQuery(String likeText, String[] moreLikeFields, Analyzer analyzer) {
+    this(likeText, moreLikeFields, analyzer, moreLikeFields[0]);
+  }
+
+  /**
+   * @param moreLikeFields
+   */
+  public MoreLikeThisQuery(String likeText, String[] moreLikeFields, Analyzer analyzer, String fieldName) {
+    this.likeText = likeText;
+    this.moreLikeFields = moreLikeFields;
+    this.analyzer = analyzer;
+    this.fieldName = fieldName;
+  }
+  
+  @Override
+  public Query rewrite(IndexReader reader) throws IOException {
+    MoreLikeThis mlt = new MoreLikeThis(reader);
+    
+    mlt.setFieldNames(moreLikeFields);
+    mlt.setAnalyzer(analyzer);
+    mlt.setMinTermFreq(minTermFrequency);
+    if (minDocFreq >= 0) {
+      mlt.setMinDocFreq(minDocFreq);
+    }
+    mlt.setMaxQueryTerms(maxQueryTerms);
+    mlt.setStopWords(stopWords);
+    BooleanQuery bq = (BooleanQuery) mlt.like(new StringReader(likeText), fieldName);
+    BooleanClause[] clauses = bq.getClauses();
+    // make at least half the terms match
+    bq.setMinimumNumberShouldMatch((int) (clauses.length * percentTermsToMatch));
+    return bq;
+  }
+  
+  /*
+   * (non-Javadoc)
+   * 
+   * @see org.apache.lucene.search.Query#toString(java.lang.String)
+   */
+  @Override
+  public String toString(String field) {
+    return "like:" + likeText;
+  }
+  
+  public float getPercentTermsToMatch() {
+    return percentTermsToMatch;
+  }
+  
+  public void setPercentTermsToMatch(float percentTermsToMatch) {
+    this.percentTermsToMatch = percentTermsToMatch;
+  }
+  
+  public Analyzer getAnalyzer() {
+    return analyzer;
+  }
+  
+  public void setAnalyzer(Analyzer analyzer) {
+    this.analyzer = analyzer;
+  }
+  
+  public String getLikeText() {
+    return likeText;
+  }
+  
+  public void setLikeText(String likeText) {
+    this.likeText = likeText;
+  }
+  
+  public int getMaxQueryTerms() {
+    return maxQueryTerms;
+  }
+  
+  public void setMaxQueryTerms(int maxQueryTerms) {
+    this.maxQueryTerms = maxQueryTerms;
+  }
+  
+  public int getMinTermFrequency() {
+    return minTermFrequency;
+  }
+  
+  public void setMinTermFrequency(int minTermFrequency) {
+    this.minTermFrequency = minTermFrequency;
+  }
+  
+  public String[] getMoreLikeFields() {
+    return moreLikeFields;
+  }
+  
+  public void setMoreLikeFields(String[] moreLikeFields) {
+    this.moreLikeFields = moreLikeFields;
+  }
+  
+  public Set<?> getStopWords() {
+    return stopWords;
+  }
+  
+  public void setStopWords(Set<?> stopWords) {
+    this.stopWords = stopWords;
+  }
+  
+  public int getMinDocFreq() {
+    return minDocFreq;
+  }
+  
+  public void setMinDocFreq(int minDocFreq) {
+    this.minDocFreq = minDocFreq;
+  }
+}